1. Field of the Invention
The present invention generally relates to a probe microscope. In particular, the invention relates to a probe microscope that includes first and second displacement detection optical systems. The first displacement detection optical system detects the displacement of a cantilever that has a probe that can be brought into contact with a measurement target object. The second displacement detection optical system detects the displacement of the measurement target object.
2. Description of the Related Art
A probe microscope that includes a first displacement detection optical system for detecting the displacement of a cantilever that has a probe that can be brought into contact with a measurement target object and a second displacement detection optical system for detecting the displacement of the measurement target object is known in the art. The known probe microscope scans the surface of a measurement target object to observe the surface profile of the measurement target object. An example of such a known probe microscope is disclosed in Japanese Unexamined Patent Application Publication No. H7-198730. The scanning type probe microscopic device (probe microscope) disclosed in the above patent document is provided with a cantilever, a probe microscope (first displacement detection optical system) for detecting the displacement of the cantilever by irradiating the cantilever with a laser beam, and a laser microscope (second displacement detection optical system) for detecting the displacement of a measurement target object by irradiating the measurement target object with a laser beam. Besides the above components, the scanning type probe microscopic device further includes an optical path changing unit for switching between an optical path for irradiating the cantilever with a laser beam and an optical path for irradiating the measurement target object with a laser beam by changing a beam direction. The scanning type probe microscopic device detects the displacement of the cantilever by means of the probe microscope and the displacement of the measurement target object by means of the laser microscope, which are switched therebetween by carrying out an optical path switchover by means of the optical path changing unit.
Since the scanning type probe microscopic device disclosed in the above patent document carries out a switchover between the detection of the displacement of the cantilever by means of the probe microscope and the detection of the displacement of the measurement target object by means of the laser microscope by selecting an optical path by means of the optical path changing unit as explained above, there is a problem in that it is difficult to measure the same region of the measurement target object. In addition, since the probe microscope and the laser microscope are configured as two microscopes separated from each other, there is a problem in that the size of the scanning type probe microscopic device is inevitably large. Moreover, such a configuration of the probe microscope and the laser microscope is disadvantageous in terms of manufacturing cost.